EUCHNER SN 12/16 mm - Manual (Page 4)

Operating Instructions Precision Multiple Limit Switches SN 12/16 mm
Correct use
Precision multiple limit switches are used for
positioning and controlling machines and in industrial
installations.
For general applications, snap-action switching
elements ES502E are used. For usage as safety
switches, only the switching elements ES508E and
ES514 with positively driven NC contacts are allowed.
The safety switches are positively driven auxiliary
power switches and comply with the requirements
as per IEC 60947-5-1 / EN 60947-5-1 annex K.
In combination with a separating safety guard , this
safety device prevents dangerous machine move-
ments from occurring while the safety guard is open.
A stop command is triggered if the safety guard is
opened during the dangerous machine function.
Before safety switches are used, a risk assessment
must be performed on the machine in accordance
with
EN ISO 13849-1, Safety of machinery. Safety related
parts of control systems. General principles for
design
EN ISO 14121, Safety of machinery. Risk
assessment. Principles.
Correct use includes compliance with the relevant
requirements for installation and operation,
particularly
EN ISO 13849-1, Safety of machinery. Safety related
parts of control systems. General principles for
design
EN 1088, Safety of machinery. Interlocking devices
associated with guards. Principles for design and
selection
EN 60 204-1, Electrical equipment of machines
Incorrect use
Precision multiple limit switches with switching
element ES502E (snap-action switching contact not
positively driven) must not be used in safety circuits.
Important:
The user is responsible for the integration of the
device in a safe overall system. For this purpose
the overall system must be validated, e.g. in
accordance with EN ISO 13849-2.
If the simplified method according to section 6.3
EN ISO 13849-1:2008 is used for validation, the
Performance Level (PL) may be reduced if several
devices are connected one after the other.
If a product data sheet is included with the product,
the information on the data sheet applies in case of
discrepancies with the operating instructions.
Safety precautions
In safety circuits, only the switching elements
ES508E or ES514 with positively driven NC contacts
are allowed.
Precision multiple limit switches in safety circuits
provide a personal protection function. Incorrect
installation or tampering can lead to severe injuries
to personnel.
Precision multiple limit switches in safety circuits
must not be bypassed (bridging of contacts),
turned away, removed or otherwise rendered
ineffective.
On this topic pay attention in particular to the
measures for reducing the possibility of bypassing
from EN 1088:1995+A2:2008, section 5.7.
Where precision multiple limit switches are used
in safety circuits, switches and trip dogs must
be fitted in such a way that they are adequately
secured against movement.
To meet these requirements:
The fixings must be reliable and must also
require the use of a tool to undo them.
The use of slots must be limited to the initial
adjustment.
Precautions must be taken to ensure that there
is no movement after adjustment (e.g. using
bolts or dowel pins).
Mounting, electrical connection and setup only
by authorized personnel.
Function
Precision multiple limit switches possess several
switching elements arranged in a row.
The switching elements are actuated by means of
plungers. Different plungers and trip dogs are used
depending on the application (operating point
accuracy and approach speed) (see Figure 4).
In general applications the plunger is actuated by trip
dogs in accordance with DIN 69639 which are
mounted with an interference fit in trip rails in
accordance with DIN 69638.
Switching elements / terminal assignment
Fig. 1: Switching elements and terminal assignment
Mounting
Precision multiple limit switches must not be used
as an end stop.
When used in safety circuits, positively mount
trip dogs on the machine/safety guard so that
they cannot be detached.
It is imperative that dimension 3 -0,5
(distance
from switch reference surface to trip dog, see
Figure 3) is maintained in safety circuits to ensure
safe contact opening.
Fit precision multiple limit switches so that
connection cables and plug connectors are not
damaged by moving parts of the machine.
Protection against environmental influences
Safety venting valves are used to equalize the
pressure to protect against the pumping action of
the plunger. They must not be sealed with paint.
Mask plunger, plunger guide, safety venting valves
and rating plate during painting work!
Electrical connection
The following applies for switches with UL approval:
For use and applications as per the requirements of
, a class 2 power supply or a class 2
transformer according to UL1310 or UL1585 must
be used.
Connection cables for precision multiple limit
switches installed at the place of use must be
separated from all moving and permanently installed
cables and un-insulated active elements of other
parts of the system which operate at a voltage of
over 150 V. A constant clearance of 50.8 mm must
be maintained. This does not apply if the moving
cables are equipped with suitable insulation materials
which possess an identical or higher dielectric
strength compared to the other relevant parts of
the system.
When switches with indicators are used, the voltage
range printed on the indicator housing must be
observed (connection see Figure 5).
Open switch cover
Conductor cross-section 0.34 ... 1.5 mm²
For design SN in LED version with switching element
ES514 and plunger spacing 12 mm the following
applies: make LED connections to the switching
element (connection see Figure 5)
For terminal assignment see Figure 1
Fit EUCHNER cable gland M20x1.5 or similar quality
cable gland with captive O-ring
Seal cable carefully. Sealing ring must be matched
to the diameter of the cable
Tighten screws for connections to the switching
element to 0.6 Nm
Close switch cover and tighten cover screws to
1.5 Nm.
Functional check
When the safety guard is open, the safety switch
must be actuated in any safety guard position
(overrun protection).
In safety circuits, check the safety function.
The machine must stop when the safety switch is
actuated.
The machine must not start when the safety switch
is actuated.
Mechanical function test
Check the actuating elements for freedom of
movement.
Electrical function test
Actuate switch and check the switching function.
Inspection and service
In safety circuits, the entire multiple limit switch
must be replaced in case of damage or wear.
Repairs must be performed only by the
manufacturer.
No servicing is required, but regular inspection
of the following is necessary to ensure trouble-free
long-term operation:
correct switching function
secure mounting of components
precise adjustment of trip dog in relation to multip-
le limit switch
dirt and wear
sealing of cable entry
loose cable connections or plug connectors.
ES 514
ES 508E
ES 502 E
Shown: switching element not actuated
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